Element, pleated paper type. A super fine 3 micron element specifically designed to protect servo valves in critical hydraulic systems. Has an additional pleated overlay of special filter material to absorb submicronic wear particles and provide additional fatigue resistance. Will fit AF-500 Series filters, requiring 6" long elements, such as AF-500-CX, AF-500-C and AF-500-CMS also AF-600-C Series filters.